Electrical transformer



March 2 1926. 1,575,341

A. A. HOWARD ELECTRICAL TRANSFORMER Filed March "7, 1925 i gmanTeammate. I

Application filed March 7,11affsn No. 13,773; I

' To d'ZZ'uihom mag/concern;- '5

. Be it known that L'AUSTINA; HOWARD, a

'l citizen of tthe} United States,- residing at ,Chicago, in the countyofCook and State of Illinois, have invente'd' anew and useful 1mproveinent in Electrical:Transformers, -'of I which the following isa'specification.

, '.This invention relates to improvements in 1 electrical transformers.-l One of the objects of the invention isito' provide aitransformer jwhich can be easily andche-aply ;madefand which i will be stro'ng anddurable. I] have r here 7 shown; the invention 1. asieinbodiedj in atransformer" such "as; isxused in; connection with radio apparatus forthe-amplification v ofgwavesiat radio frequency.

Inmaking such; transformers, two coils are employed, a primary coil anda secondary 1 coil. .The'se" coils are arranged in inductive- 20.properly in thisposition. Y the use of -my inventionI am i simplemanneni i I Bythe use of my invention- I am able to produce'a coil in whichthe dielectric losses :fiare reduced,the staticcharges lessened, and"the-capacity of theltransformer lowered. Other'features and advantagesof my inv vention will appear'more fully as I proceed .39 I v f In thatformof device embodying the fea- ;-turesf of my invention shown in theaccomrelation toeach other and must be supported able to do this in avery with my specification.

, panyingfdrawings, Figure '1 is a top plan view of afcompletetransformer, Fig. 2 is a view taken as indicated by the line 2 of Fig.,1,1Fig;3.-isja;,topplan view of the dielectric,

for insulator'supportfor, the wires forming a a1section of tubing with arelatively thick, y walland provided with a plurality of slots. 11ther'ethrough, the series of such slots expart of the transforrner, andFig. 4 is a fragmentary verticalsectlonal v1ew taken as indicated bytheline 4 ofFig. 2.

"As shown in the drawings, 10 indicates a cylindrical supporting memberhere shown as' made of dielectric or insulating material such as fibre,bakelite, hard rubber or the like. ,This cylindrical member is virtuallytending'around the entire circumference of the'support'. The slots 11,it willbenoted,

are not parallel to the axis of the support but each is slanted'slightlyfrom end to end as. most clearly shown 'inFig. 3. I have indicated theremaining portionsof-the cyilindricalshellor support between the slotsll 'by the reference numerals 12, 12, and it fications. V V

struction and arrangement may be made will be noted that these remainingportionsy 12,12 virtuallyconstitute'barsfor stripsupon which the wiresare wound as will be explained more 111 detail herelnafter.

By cutting the slots 11 in'the dielectricg upport 10, the "dielectriclosses are reduced,

the static charges lessened and the capacity i of th'etransformerlowered. I On the outer surfaces of the bars or strips 12,=there are cutgrooves 13, 18, the different cuts on said portions togethercons'tituthig one continuous spiral groove on the outer surfacef-theEmembenI O except' jas said groove isinterruptedbythe slots '11,11.

The turns of this groove 13 are spaced apart the primary or inner coilfrom the secondary V or outer coil.- Obviously, the wall of the member10 must be of sufficient thickness to permit the requisite depth of thegroove 13:

and still furnish'sutiicient strengthto support the wires.

14 indicates the wire forming the inner or primary coil. This wire iswound in the bottom of the cuts 13 which, as stated above,

together form a continuous spiral groove.

, The wire is formed in a continuous spiral c011 and brldges across thegaps 11, 11.

The wire 14: maybe bare as shown or it may be insulated. Preferably thesupport member 10 is made of insulating mate ria, as stated above, sothat the wire 14 may be bare; and when such wire is used the turns areproperly spaced and insulated from each other by the groove 13.

- After the primary coil 14: has been wound on. the support, there iswrapped around the same a sheet of any suitable material such Thismaterial 1 covers the grooves 13. After this paper is in place thereiswound thereon the second' as, for example, paper 15.

arycoillti here shown as consisting of insulated wire. The sheetofmaterial 15 prevents the turns of the coil 16 from enteringlVhileIhave shownand described certain embodiments of my invention, it is tobe understood that it is capable of many modi- Changes, therefore, inthe con j '5 broadly as possible in viewoffthdprior art;

' by LettersPathtjis? v z j ,r VVhat I claini -asfnem; andflsirertoiseciuref 1 I v anothe rwlite "wQund on the outervsurfaqejosaldgsheatlrlate tial.,f Y

fpopt' a lspibeing proy gled with Cutaway ,.p0'r- 1 13110113,; said,c'ut away;pcz wizi rls interrupt ng l eil'tel ,thavnflt-he dija ine te iof the wire laid I ftherem; a sheet Qf, maijenal wound on sa d gsqppor'tiifid"lylilg :over said fgroow'zegland ogtions uptinggzsa 1 saidspiralgroove 'I- Wi1 6 laid in thebottbmv ofsaid groove and spanning;sai'chgut away gmsf the rfdepth off sa d groqvei hem-g anothiar 'Wirewou d on the Qiiter siirfac of ,111 its outgr' surfae, said V 7 v March,A; D. ;1 925. I cutaway portions, said slots" grafcer {than the diametijof fth wirej laid supp01t" .aiid lying. over-said ,grdovef; and;

3; A ifdviqe o f f thg {ciiarapte ii desg'ribd comprising; yh nd-i' calsupport havmg 31 1 2211 groove: -7 its v P te Surface; i P

P l b ngIp ovi d ith la mg ldilgl; tud nal slo t s or vcut-"awaypqrtions sgild slgts 1 gr put away pgi 'clons interrupting";

groove-and spanning said slots vqr cufc I port ons,v thg depth j of,salcl grpov :belng greater than the diameter oi the Wirgglgud therein};a sheet of liiat g igil wou id on aid

